The present invention relates to corrugated fins for heat exchanger to be interposed between flat tubes or to be installed in the flat tube, ridges and furrows being alternately arranged on a rising wall surface and a falling wall surface thereof.
As the corrugated fins for heat exchanger which make clogging difficult to occur and which can be applied also to a gaseous body which contains many particulate matters such as dust, for example, the fin described in the following Patent Literature 1 is known and is used in a heat changer and an exhaust heat exchanger of construction machinery.
The invention described in Japanese Patent Laid-Open No. 2007-78194 is a rectangular-wave-shaped corrugated fin in which peak parts and valley parts of the wave have run meandering in a longitudinal direction as shown in FIG. 16 and FIG. 17 (hereinafter, referred to as a conventional type corrugated fin). The fin described in Japanese Patent Laid-Open No. 2007-78194 is used as an inner fin to be installed in a tube and which stirs a gaseous body which flows through within it by making it meandering from the upstream side to the downstream side so as to reduce a boundary layer generated on the wall surface as much as possible.